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In this work, the one-step stereochemical antimicrobial finishing of cotton textiles (CT) was achieved by the oxidative copolymerization of a dopamine-menthol derivative (DAM) and dopamine (DA). The obtained DAM-modified CT (P(DAM-co-DA)-CT) exhibited broad-spectrum microbial anti-adhesion properties against bacteria (E. coli and P. aeruginosa), including superbugs (MRSA and VREF), and fungi (A. niger, A. flavus, M. racemosus and P. chrysogenum). Because of its unique stereochemical antimicrobial mechanism, the obtained P(DAM-co-DA)-CT is a non-releasing antimicrobial material that causes no skin sensitization and exhibits good biocompatibility. The coating was also found to enhance the UV-resistant and mechanical properties of the CT. Furthermore, it displayed durable washing fastness and antimicrobial properties after the endurance of 30 laundering cycles. The observed achievements provide a broader understanding of stereochemical antimicrobial surfaces and endow this method with wider applications.

Highly luminescent metal nanoclusters (MNCs) with aggregation-induced emission (AIE) have emerged as a new class of functional materials, which could be deployed to address challenging issues in di...

The strategy to improve the photocatalytic removal efficiencies towards organic pollutants is still a challenge for the novel Sillen–Aurivillius perovskite type Bi4NbO8Cl. Herein, we report carbon-supported TiO2/Bi4NbO8Cl (C-TiO2/Bi4NbO8Cl) heterostructures with enhanced charge separation efficiency, which were fabricated via molten-salt flux process. The carbon-supported TiO2 particles were derived from MXene Ti3C2 precursors, and attached on plate-like Bi4NbO8Cl, acting as electron-traps to achieve supressed recombination of photo-induced charges. The improved charge separation confers C-TiO2/Bi4NbO8Cl heterostructures superior photocatalytic performance with 53% higher than pristine Bi4NbO8Cl, towards rhodamine B removal with the help of photo-induced holes. Moreover, the C-TiO2/Bi4NbO8Cl heterostructures can be expanded to deal with other water contaminants, such as methyl orange, ciprofloxacin and 2,4-dichlorophenol with 44, 25 and 13% promotion, respectively, and thus the study offers a series of efficient photocatalysts for water purification.

Ultrasmall silver nanoclusters (Ag NCs) with rich surface chemistry and good biocompatibility are promising in antibacterial application, however, further development of Ag NCs for practical settings has been constrained by their relatively weak antibacterial activity. Using the nutritionally-rich medium for bacteria (e.g., Luria-Bertani (LB) medium) to coat active Ag NCs could further improve their antibacterial activity. Here, we provide a delicate design of a highly efficient Ag NCs@ELB antibacterial agent (ELB denotes the extract of LB medium) by anchoring Ag NCs inside the ELB species via light irradiation. The as-designed Ag NCs with bacterium-favored nutrients on the surface can be easily swallowed by the bacteria, boosting the production of the intracellular reactive oxygen species (ROS, about 2-fold of that in the pristine Ag NCs). Subsequently, a higher concentration of ROS generated in Ag NCs@ELB leads to enhanced antibacterial activity, and enables to reduce the colony forming units (CFU) of both gram-positive and gram-negative bacteria with 3–4 orders of magnitude less than that treated with the pristine Ag NCs. In addition, the Ag NCs@ELB also shows good biocompatibility. This study suggests that surface engineering of active species (e.g., Ag NCs) with nutritionally-rich medium of the bacteria is an efficient way to improve their antibacterial activity.

Metal-nitrogen doped carbon is a class of promising catalysts to replace Pt to catalyze the oxygen reduction reaction (ORR). Herein, a novel three-dimensional (3D) Fe-N-C nanosheets grown on interconnected carbon skeletons is fabricated by a facile route, i.e., in situ polymerization of aniline to obtain polyaniline nanosheets on 3D melamine foams and subsequent pyrolysis of the composites. The catalyst exhibits comparable catalytic activity but superior long-term stability to the commercial 20% Pt/C for the ORR in alkaline electrolyte in terms of the onset potential (1.01 V vs. RHE) and the half wave potential (0.86 V vs. RHE). The outstanding catalytic performance was ascribed to the populated active sites taking advantage of the large surface area, the superior electro-conductivity and the facilitated mass transportation by virtue of the unique hierarchically interconnected porous carbon structure. This work is expected to provide a new avenue to fabricate 3D interconnected porous composites for energy conversion and storage.

Utilizing more solar energy and suppressing recombination of photo-induced charges are primary issues for photocatalyst's design. In this work, BiOBr was introduced into CdTe/TiO2 to construct a novel ternary BiOBr/CdTe/TiO2 composite via a facile solvothermal method. The composition, morphologies, optical properties, specific area, and photocatalytic performances were all investigated in detail. The heterojunction among three-dimensional TiO2 particles, BiOBr and CdTe acts an interfacial channel to boost the charges migration. As a result, the ternary BiOBr/CdTe/TiO2 heterojunctions exhibited higher visible light photocatalytic activities on photo-decolorization of methyl orange (MO) than the pure TiO2 and the binary CdTe/TiO2 and BiOBr/TiO2. Furthermore, the ternary BiOBr/CdTe/TiO2 composites were converted into hollow structure, and showed the better photocatalytic performance, reaching 75% degradation towards MO in 120 min. This study provided an attractive thought to design highly efficient photocatalysts, which possessed a promising for wastewater purification.

Hollow and heterostructured architectures are recognized as an effective approach to improve photocatalytic performance. In this work, ternary TiO2/CdTe/BiOI with hollow structure was constructed via a step-by-step method. In addition, the effect of TiO2 structural regulation and the energy band alignment of BiOI and CdTe quantum dots (CdTe QDs) with TiO2 in TiO2/CdTe/BiOI on photocatalytic dye removal were also studied. The results reveal that the TiO2/CdTe/BiOI heterostructures with hollow substrates exhibit much higher photocatalytic activities than pure TiO2, P25, TiO2/CdTe, and TiO2/BiOI and ternary TiO2/CdTe/BiOI with solid substrates. For TiO2(H)/CdTe/BiOI, several synergistic factors may be responsible for the remarkable visible-light photodegradation performance, such as strong visible-light absorption by BiOI and larger specific surface area.

Self-supported nanoporous metals are promising catalysts and battery materials due to their continuous channels, excellent conductivity and high surface area. In this work, we found that Cu2+ cations could promote the spontaneous formation of AgCl on Ag surface via microcell reactions. Applying a potential to the silver electrode promotes the surface enrichment of Cu2+ cations, and further speeds the formation of AgCl. After electro-reduced, AgCl was transformed to self-supported silver electrode with nanoporous structures, which shows good catalytic activity for the oxygen reduction reaction and electrochemical stability together with superior methanol tolerance property, compared to the pristine silver electrode. The approach used in this work provides an alternative way to prepare self-supported nanoporous metals.

Construction of semiconductor heterojunctions is an efficient strategy to improve photo-induced charges separation and thus enhance photocatalytic activities. Herein, g-C3N4/TiO2 heterostructures were prepared via a facile thermal procedure, with TiO2 nanorods as matrix and g-C3N4 as visible-light sensitizer. Heterojunctions formed while precursors cyanamide polymerized to g-C3N4 and protonated titanate nanotube (H-TNTs) dehydrated and shrinked to TiO2 nanorods. Notably, confined polymerization of g-C3N4 occurred at both external surface and internal space of H-TNTs with the assistant of vacuum treatment, while NH3 released from cyanamide decomposition yielded abundant oxygen vacancies (VO) in TiO2 nanorods. Compared with pristine TiO2 nanorods, the heterostructured g-C3N4/TiO2 nanorods possess 1.7 times more active in photocatalytic removal of organic dye Orange II. A mechanism was proposed for heterostructured g-C3N4/TiO2 nanorods, being attributed to synergistic increasing light harvesting by VO and charges separation by heterojunctions.

A series of novel binary TiO2/BiOX (X = Cl, Br, I) and ternary TiO2/CQDs/BiOBr hybrid photocatalysts were prepared through a facile hydrothermal method. TiO2/BiOX heterostructures were fabricated by varying the halogen ions. The photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV–Vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. Among the binary TiO2/BiOX, TiO2/BiOBr showed the most preferable photocatalytic activities due to suitable band gap alignment and photo stability, reaching almost 80% MO degradation during 180 min irradiation under simulated sunlight. Moreover, the effects of synthesis temperature, Ti/Bi ratio on the composition and structure were investigated, the results indicated TiO2/BiOBr with Bi/Ti = 10% prepared at 120 °C possessed the best photocatalytic performance. Carbon quantum dots were introduced to accelerate electrons transfer at interface or prevent charges recombination on the surface, resulting a much better photocatalytic performance for TiO2/CQDs/BiOBr hybrid photocatalysts.

A two dimensional ion chromatography (2D-IC) method was improved for the simultaneous determination of six cations and seven anions using one-valve switching after injection and conductivity detector. The trap conditions and valve-switch timing were optimized. The method has good accuracy and sensitivity for the simultaneous separation of inorganic anions and cations with a mean correlation coefficient of >0.99, repeatability of 0.60%–3.0% for eight replicates, reproducibility of 0.78%–3.1%, and spiked recovery rate of 88.7%–110%. The method was successfully applied to the analysis of inorganic anions and cations in four kinds of mineral water and can completely satisfy the demand of water quality monitoring.

BiVO4/TiO2 nanocomposites were fabricated by a facile wet-chemical process, followed by the synthesis of TiO2 hierarchical spheres via hydrothermal method. The BiVO4/TiO2 nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV–Vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. The results showed that prepared TiO2 presented hierarchical spherical morphology self-assembled by nanoparticles and an anatase–brookite mixed crystal phase. The introduction of monoclinic BiVO4 components retained the hierarchical structures and expanded the light response to around 510 nm. Type II BiVO4/TiO2 heterostructured nanocomposites exhibited improved photocatalytic degradation towards methylene blue under visible-light irradiation, especially for the composite photocatalysts with atomic Ti/Bi = 10, which showed double degradation rate than that of pure BiVO4. The enhanced photocatalytic mechanism of the heterostructured BiVO4/TiO2 nanocomposites was discussed as well.

Recently, carbon dots have emerged as novel luminous materials due to their excellent luminous performance. However, it is still challenging to obtain high quantum yields of red emission in carbon dots. Herein, we synthesized a new type of high efficiency red emission-carbon dots from 1,4-phenylene diisocyanate by a solvothermal method. Furthermore, the carbon dots were used to fabricate trichromatic white LEDs that possess a high luminous efficacy and color rendering index. In this study, we propose an approach for achieving high carbon dots with quantum yields by introducing more conjugated nitrogen groups in a graphitic layered structure. Moreover, the high efficiency red emission carbon dots can greatly promote carbon dots’ application in white LEDs, demonstrating that the as-prepared carbon dots are promising materials in LEDs, displays and even in other light applications.

As one of the essential components for electronic and optical devices, coating materials have been researched for many years due to the unique mechanical and optical properties. Preferably, the coating materials should be highly transparent, superhydrophobic (self-cleaning), mechanically robust, and durable so as to meet the requirements for practical applications. However, it remains a big challenge to improve the mechanical strength and durability of the coating without sacrificing its transparency and hydrophobicity through a facile and low-cost technology. Herein, an organic/inorganic hybrid coating consisting of self-designed resin with long-fluorine groups and hydrophobic silica nanoparticles was fabricated via a facile sol-gel/spin coating technology. The as-synthesized hybrid coating inherited the advantages of the self-designed resin (hardness and transparency) and hydrophobic nanoparticles (nano-structure) which displayed excellent superhydrophobicity (CA: 160.1 ± 1°, SA: 7 ± 1°, σ2: 0.862), outstanding mechanical property (CA was maintained at 140° after 200 tape peeling cycles), and high transparency (average of 93.6 %). Most importantly, the coating exhibits outstanding durability towards strong acid, UV light, water droplets, and heat, which can be crucial for its practical application especially in harsh conditions. This work describes a highly transparent, superhydrophobic (self-cleaning), mechanically robust, durable coating and promising applied in the industrials.

Multifunctional enzymatic nanomaterials (nanozymes) with good biocompatibility, strong enzymatic activity, and substrate specificity are the desired alternatives to natural enzymes. Here, the design of a peroxidase mimetic nanozyme capable of detecting and depleting glutathione (GSH) in the bacterial cells is presented. The nanozyme palladium-iron nanostructure decorated graphdiyne nanosheet (PdFe/GDY) was prepared by a facile hydrothermal approach. It can efficiently catalyze the decomposition of H2O2 to produce •OH by a peroxidase-like mechanism. Surprisingly, the PdFe/GDY nanozymes can detect GSH in bacteria with excellent specificity and ultra-low detection limit of 24.45 nM. Moreover, the PdFe/GDY nanozymes can consume GSH for bacterial disinfection with killing efficacy > 99.99%, promote wound healing and do not cause significant toxicity in vitro and in vivo. To our knowledge, this is the first example of a GDY-based nanozyme biosensor and antibacterial agent. Collectively, this work would be indicative to construct GDY-based nanozymes in clinical diagnosis and sterilization.

Organosilane-functionalized carbon dots (SiCDs) with green emission were prepared by one-step solvothermal method. Anhydrous citric acid and N-(2-aminoethyl)-3-aminopropyltrimethoxy-silane (KH792) ...

Bimetallic catalyst Ni–Fe/SiO2 microspheres were obtained by reducing bimetallic (Ni,Fe2+)3Si2O5(OH)4 microspheres with controllable morphology structure in situ under the hydrogen atmosphere at 650 °C, which are synthesized via one-step self-template method under hydrothermal conditions. The TEM images indicate the formation process of the different morphology and the synthesis conditions of bimetallic Ni–Fe silicate were obtained. Bimetallic catalyst Ni–Fe/SiO2 (reduced) hollow microspheres had the smaller surface area and the bigger pore diameter than that of (Ni,Fe2+)3Si2O5(OH)4 (unreduced) hollow microspheres because the reduction reaction under high temperature may make part pores in nanosheets collapsing and metal particles aggregating easily for the strong magnetism. For synergistic effect of nickel ion and iron ion, the reaction conditions of the chosen catalyst with higher activity were decreased from 140 °C–24 h + 180 °C −12 h for iron silicate hydroxide to 140 °C–12 h. Ni–Fe/SiO2 core-shell microspheres exhibited excellent catalytic activity with a conversion of nitrobenzene reaching 94% within 2 h, which is 82% higher than Fe/SiO2.

In this work, silane-functionalized carbon dots with green and red emission (G-SiCDs and R-SiCDs) were prepared via a one-step solvothermal method. Red LEDs were fabricated using a combination of R-SiCDs and blue LED chips since there have been few reports on red LEDs that have carbon dots as a converter. Also, different ratios of G-SiCDs to R-SiCDs were adjusted so they could serve as optical converters in trichromatic WLEDs. Compared to G-SiCD-based dichromatic WLEDs, the color rendering index (CRI), which represents the true color of irradiated objects, of R-SiCD- and G-SiCD-based trichromatic WLEDs was found to be significantly improved from 58 to 88. The CIE coordinates of the G-SiCD- and R-SiCD-based trichromatic WLEDs were very close to and were even the same as pure white light (0.33, 0.33). G-SiCDs and R-SiCDs have a similar functional alkoxysilane group, thus they will show good compatibility and can co-condense with each other to form a 3D cross-linking structure. What's more, environmental SiCDs have the potential to be luminescent and encapsulation layers simultaneously in trichromatic WLEDs. This strategy will help to avoid traditional compatibility problems between luminescent and encapsulation materials in WLEDs. The as-prepared polymerizable SiCDs could provide a new opportunity to simplify the preparation process and improve the optical performances of WLEDs.

Water electrolysis is a clean and effective strategy for mass production of hydrogen. Iron phosphide is a fascinating candidate for hydrogen evolution reaction (HER) among the reported Pt-free metal catalysts; however, the catalytic activity of FeP is far behind Pt. Herein, we prepared a highly efficient and durable mesoporous Mn-doped FeP (Mn-FeP) catalyst for HER via a facile and controllable synthesis route. It is manifested that Mn doping leads to improved electroactivity of mesoporous FeP in a wide pH range. For the mesoporous Mn-FeP catalyst, the overpotential is 69, 157, and 173 mV in H2SO4, PBS, and KOH electrolytes at 10 mA cm–2, respectively, which is 21, 40, and 54 mV less than that of its counterpart mesoporous FeP. Furthermore, it can be concluded that the enhanced HER activity of Mn-FeP is ascribed to both the appropriate thermoneutral hydrogen adsorption free energy and the accessible active sites thanks to the mesoporous structure from the density functional theory (DFT) calculation and th...

In order to improve the high-temperature oxidation resistance of the traditional phenolic resin binder, nickel nitrate was added into the phenolic resin as the catalyst precursor, while carbon nanotubes (CNTs) could be in-situ formed inside the pyrolytic carbons during the pyrolysis process. The influence of pyrolysis temperatures on the formation of CNTs in pyrolytic carbons was investigated. The results showed that CNTs with the diameter of 20–40 nm were formed in pyrolytic carbons, while the nickel nitrate and the gases released through the pyrolysis of phenolic resin were respectively served as the catalyst and the carbon sources. Meanwhile, the increased temperature could promote the formation of the CNTs, and further improve the graphitization degree and the high-temperature oxidation resistance of the pyrolytic carbons. The high-temperature oxidation resistance of corundum graphite composite materials could be effectively improved by using phenolic resin with nickel nitrate as the binder, which demonstrates it to be a promising binder for high-temperature application.

A mechanically robust, transparent, solvent-free, and self-cleaning coating (GPMS-DTDA/PFTS) was fabricated based on the co-hydrolysis/condensation of the Dibutyltin dilaurate, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (curing agent), while the different amount of 1H,1H,2H,2H-Perfluorodecyltrimethoxysilane were added to the system to reduce the surface energy of the coating. The morphology and properties of the polysiloxane-based coating were characterized by SEM, FTIR, UV–vis-NIR. The as-synthesized GPMS-DTDA/PFTS-based coating displays excellent performance with the hardness of 8H, superior adhesion (5B), high transmittance (95.2 %), hydrophobicity (CA: 107°) as well as outstanding properties of self-cleaning and weather resistance.

Hierarchical maghemite (γ-Fe2O3) microstructures have been synthesized by a facile and efficient templating approach involving the bottom-up formation and the subsequent thermal decomposition of the polymeric iron (III) acetate. The hierarchical microstructures of γ-Fe2O3 are derived from the template, which are assembled by porous nanobelts composed of nanocrystals. When evaluated as an anode material for lithium ion batteries, the hierarchical γ-Fe2O3 microstructures exhibit excellent electrochemical lithium storage performances including high reversible capacity (1300 mAh g−1 at 0.1 A g−1), excellent rate capability (383 mAh g−1 at 5 A g−1) and good cyclic stability (700 mAh g−1 after 100 cycles at 1 A g−1), The excellent performances are explored in terms of hierarchically porous structures, which promotes the fast and effective lithium ion transport, and buffer the large volume expansion during the charge and discharge cyclings.

Novel porous coordination polymers (PCPs) modified with sulfonic acid/phosphotungstic acid (PTA) were prepared by hydrothermal method via one-pot self-assembly. The materials were characterized by FTIR, XRD, TEM, SEM-EDS, N 2 adsorption/desorption, TG, NH 3 -TPD, etc., and have been used as solid acid catalysts for reproducible glucose transformation to 5-hydroxymethylfurfural (HMF) in environmentally friendly solvents. With PCP(Cr)-SO 3 H·Cr(III) as catalyst, over 99.9% glucose conversion and an excellent HMF yield of 80.7% were obtained at 180 °C for 4 h in water, with THF as the online extraction agent for HMF. In this system, the staple glucose material could successfully substitute the expensive fructose (HMF yield = 85.3%). A possible mechanism of glucose conversion and the formation procedure of byproduct were deduced and analyzed. The catalyst could be easily reused with good reproducibility and low wastage of active metal, showing a good prospect for high value applications of glucose.

Bifunctional lignosulfonate-based catalysts (LS-M) with Lewis acid and basic sites were designed and prepared by immobilizing metal ions on lignosulfonate. Catalysts were characterized by XRD, XPS, SEM, EDX, TEM, TGA, NH3/CO2-TPD and FTIR, and applied in transformation of carbohydrate biomass to furan derivatives (HMF/furfural) in mixed water/THF systems. With LS-Cr as catalyst, the optimized yields of HMF from cellulose, glucose and mannose were 46.3%, 60.4% and 68.8%, and that of furfural from xylan, xylose and arabinose were 40.2%, 73.1% and 51.6%, respectively. The catalysts could be easily recycled with negligible wastage of the active metal ions.

In this work, the self-doped polyaniline-molybdenum disulfide (SPAN-MoS2) nanocomposite with outstanding conductivity and synergistic electrochemical activity was prepared by ultrasonic exfoliating method. In the ultrasonic process, the negatively charged SPAN served as an intercalator to result in few-layers MoS2 nanosheets exfoliated from bulk MoS2. The obtained SPAN-MoS2 nanocomposite owns large conjugated structure and rich negative charge because of the strong π-π* stacking interaction and electrostatic repulsion, which can enhance the adsorption of some conjugate structured and positively charged biomoleculars, such as vitamin B2 (VB2). The results also displayed that the electrochemical responses were further affected by the mass ratio and the ultrasonication time.

Polysiloxane coatings prepared by pre-hydrolysis/condensation of methyltrimethoxysilane (MTMS), etraethoxysilane (TEOS), methyltriethoxysilane (MTES) and polydimethylsiloxane (PDMS) in the presence of acid solution were presented in this paper in order to explore their potential use as protective and self-cleaning agents for car surface. The hardness and adhesion on the substrate properties of coatings were thoroughly examined by pencil hardness tester and adhesion tester. Contact angle meter was used to measure the hydrophobic angle properties of coatings. All the properties of coatings were related closely to the composition of coating and the hydrolysis degree of organoalkoxysilane. We found that the Scratch hardness can be improved by the controlling of TEOS quality ratio and acidity conditions, while more dosage of MTMS, MTES and PDMS favor raising the hydrophobic angle. Excellent adhesion property of paint coat was obtained with the presence of γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH-560). Whatever, the best self-cleaning coatings with excellent hardness and adhesion on the substrate was sample A4 synthesized by a sol–gel process of low-cost organoalkoxysilane, prepared at the quality ratio of (MTMS):(TEOS):(MTES):(PDMS):(KH-560) of 8:7:4:4:4 and water-to-precursor quality ratio of 1:7. Finally, ambient-curable self-cleaning coating suitable for large area application was obtained. The scratch hardness and adhesion strength of the coatings was 3H and 0 after hardening with a high speed, respectively. The contact angle after UV aging of the coating was 92°. The transmittance of the coating exceeded 98.5%. Meanwhile, the coating has good resistance to solvent and weather resistance.

Porous Prussian blue (PB) films were successfully electrodeposited on Ni3Si2O5(OH)4 hollow nanosphere coated indium tin oxide (ITO) glass. Ni3Si2O5(OH)4 hollow nanospheres hydrothermally synthesized using SiO2 nanospheres as templates play a key role in the formation of porous PB films. The as-prepared PB films exhibit larger transmittance change, faster switching response and higher coloration efficiency than those of dense PB films directly electrodeposited on ITO glass. The enhanced electrochromic properties are attributed to the large specific surface area and porosity of the PB films which bring a high diffusion rate and short diffusion path length of ions.

Carbon nanotubes (CNTs) supported Pd catalysts (1 wt% and 5 wt%) were prepared by a conventional impregnation method and tested in liquid-phase hydrodechlorination (HDC) of para-chlorophenol (p-CP) under mild conditions (313 K and atmospheric pressure) with H2. CNTs as a catalyst support offered better performance than activated carbon (AC). The conversion of p-CP reached 72% and 82% over 5 wt% Pd/AC and 5 wt% Pd/CNTs, respectively, within 30 min. When the content of Pd was reduced to 1 wt%, the conversion of p-CP over Pd/AC and Pd/CNTs was 55% and 83%, respectively. The mechanism of this phenomenon was studied through catalyst characterization (XRD, TEM, and BET). The abovementioned results indicated that the different activities of the catalysts over different supports mainly resulted from the porous structure of the supports and nanoparticle diameters of the active metal.

Molybdenum disulfide (MoS2) has emerged as a promising electrocatalyst for catalyzing protons to hydrogen via the so-called hydrogen evolution reaction (HER). In order to enhance the HER activity, CTAB (cetyltrimethyl ammonium bromide)-incorporated MoS2 ultrathin nanosheets with high specific surface area and more catalytic active sites have been successfully synthesized via a facile surfactant-assisted hydrothermal approach. Adding CTAB to the hydrothermal process can effectively regulate both structural and electronic benefits by controllable disorder engineering and simultaneous CTAB incorporation in MoS2 catalysts, leading to a higher specific surface area, more catalytic active sites and better electrical conductivity for improving HER activity. The optimized CTAB-incorporated MoS2 ultrathin nanosheets exhibit excellent activity for HER with a small onset potential of 88 mV, a low Tafel slope of 55 mV dec−1, and relatively good stability.

In this paper, TiO2 photoanodes were doped with yttrium under different doping concentrations via hydrothermal method and further employed to assemble dye-sensitized solar cells (DSSCs). XRD, XPS, SEM, TEM, UV–Vis DRS and PL measurements were carried out to investigate the yttrium doping effects on crystal structure, chemical status, optical properties and dye loading capacity of the photoanodes. The photovoltaic performance of the photoanodes with various yttrium doping concentration was measured by recording the photocurrent-photovoltaic curves, and the result indicated that TiO2:0.006 Y exhibited the best power conversion efficiency with high short circuit current density (Jsc) and open circuit voltage (Voc). This improvement may be due to the enhanced visible light harvesting, increased dye loading capacity and reduced photoelectron recombination. Keywords: Dye sensitized solar cells, TiO2 photoanode, Rare earth doping, Yttrium

Bi4NbO8Cl is a novel bismuth-based catalyst with a 2D sheet structure for photodegradation under visible light irradiation. However, Bi4NbO8Cl semiconductor has low quantum efficiency, as well as the photogenerated electrons (e-) and holes (h+) tend to recombine in a single semiconductor, thereby decreasing their degradation efficiency. Hence, in this work, Bi2O3/Bi4NbO8Cl 0D/2D heterojunctions containing Bi2O3 quantum dots were prepared to enhance the photocatalytic performance, in which e- and h+ were separated and transferred to different semiconductors for oxidation and reduction, respectively. Compared to bare Bi4NbO8Cl, the photocatalytic activity of 0.5 Bi2O3/Bi4NbO8Cl increases by 2.6 times in the degradation of Rhodamine B since the formation of heterojunctions. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) has confirmed the formation of heterojunction. The photoluminescence (PL), photocurrent, and electrochemical impedance spectra (EIS) tests indicate that the quantum efficiency has been improved. This research may be valuable for the industrial application of photocatalysts and provide a new idea for designing photocatalysts.

Electrocatalysts of NiCoFe hydroxides have been prepared successfully by a simple hydrothermal method, which show excellent electrocatalytic properties. (delivering 10 mA cm−2 current density at 230 mV, with a Tafel slope of 72.7 mV·dec−1). Furthermore, in order to further improve its electrocatalysis properties, the NiCoFe hydroxide is reprocessed by vulcanizing and acid etching, respectively. The electrocatalytic properties of the NiCoFe hydroxides after vulcanization is further improved (delivering 10 mA cm−2 current density at 200 mV, with a Tafel slope of 46.3 mV·dec−1). Similarly, acid etching is also a simple and effective method to promote the OER catalytic activity, which resulted in an exfoliation process and multiple defects. The NiCoFe LTHs is stripped into a thinner nanosheet structure, and the electrochemical analysis shows excellent electrocatalytic properties (delivering 10 mA cm−2 current density at 184 mV, with a Tafel slope of 37.8 mV·dec−1). Both vulcanization and acid etching show better oxygen evolution capability than the pristine LTHs in alkaline conditions with a small Tafel slope and good durability. This work will break a new and inexpensive path to promote the catalytic capability in an alkaline condition.

The strategy to improve the photocatalytic performance is still a challenge for the novel Sillen-Aurivillius perovskite type Bi4NbO8Cl. Herein, heterostructured Bi/Bi4NbO8Cl was fabricated via in-situ solvothermal method, without the additional introduction of Bi-sources. Simultaneously, the amount of oxygen vacancies (OVs) were increased, as the [Bi2O2] blocks released in the solvothermal process to serve as precursors for Bi particles. Due to the large work function of Bi, a Schottky barrier formed at the Bi/Bi4NbO8Cl interface, promoting photo-induced charge separation generated in the Bi4NbO8Cl semiconductor, supplying more holes for the organic compounds decomposition, which could be widely applied in water decontamination. Furthermore, the OVs facilitate the consumption of photo-induced electrons by assisting oxygen activation to produce superoxide radicals (·O2−), leaving more holes in the valence band of Bi4NbO8Cl, and thus result in the enhancement of Rhodamine B (RhB) degradation by 1.82 times over Bi/Bi4NbO8Cl photocatalysts. Through the synergistic effect of Bi and OVs, the Bi/Bi4NbO8Cl also exhibits enhanced photocatalytic performance towards various organic water-contaminants, such as methyl orange, acid orange 7, p-nitrophenol and tetracycline hydrochloride.

Altering the semiconductor composition and suitable energy levels to form a cascade structure is a feasible approach to achieve superior photocatalytic activity. In this study, Bi4NbO8Cl was prepared by a ball milling-calcination method. And one-pot hydrothermal process was developed as a new strategy to synthesize ternary Bi4NbO8Cl/BiOCl/Nb2O5 (BBN) composites, where ultrafine Nb2O5 nanoparticles and BiOCl were in-situ grown and loaded on the surface of Bi4NbO8Cl using NbCl5 as raw material. An enhanced photocatalytic performance towards RhB removal by Bi4NbO8Cl/BiOCl/Nb2O5 is assigned to the in-situ formation of intimated interfaces contacts among Bi4NbO8Cl, BiOCl and Nb2O5, and suitable conduction band (CB) alignments in the ternary hybrid. The staggered energy levels inhibit the recombination of photoinduced electron-hole pairs and increase the separation efficiency of charge carriers, subsequently enhances the photocatalytic efficiency.

A deep understanding on the luminescence property of aggregation-induced emission (AIE) featured metal nanoclusters (NCs) is highly desired. This paper reports a systematic study on enhancing the luminescence of AIE-featured Au NCs, which is achieved by Ag doping to engineer the size/structure and aggregation states of the AuI -thiolate motifs in the NC shell. Moreover, by prolonging the reaction time, the luminescence of the as-synthesized AuAg NCs could be further tailored from orange to red, which is also due to the variation of the AuI -thiolate motifs of NCs. This study can facilitate a better understanding of this AIE-featured luminescent probe and the design of other synthetic routes for this rising family of functional materials.

Molybdenum phosphide, as a promising electrocatalyst for the hydrogen evolution reaction (HER), its activity suffers from two main limitations: low active surface area and unsatisfactory electrical conductivity. Herein, inspired by the neural network, we construct a novel artificial neural network-like molybdenum phosphide composite (denoted as MoP@NC-MF), using three-dimensional (3D) melamine resin foams as the scaffold. The neural network-like MoP@NC-MF composite consists of carbon-wrapped MoP nanoparticles of abundant active sites as the “neurons” and N-doped carbon as the “axons”. The MoP@NC-MF composite exhibits high electrocatalytic activity and stability for HER with a low overpotential of 125 mV required to achieve a current density of 10 mA cm–2 and a small Tafel slope of 53.0 mV dec–1 under acidic conditions, which is one of the best HER electrocatalysts among the reported single molybdenum phosphide materials. Such a superior performance of the MoP@NC-MF composite is attributed to the unique ne...

In this Letter, high-quality carbon quantum dots (C-QDs) with an average size of 15 nm are synthesized by using a solvothermal method. A C-QD saturable absorber mirror (SAM) was prepared, characterized, and employed as an ultrafast optical switch successfully in a 1.0 μm solid-state laser. The saturable absorption effect (at 1 μm) far away from the linear absorption band of the C-QDs could be attributed to two-photon saturable absorption, which has a native characteristic of wavelength selectivity. The modulation depth (ΔT) and saturable energy intensity (ϕs) of the C-QD-SA was measured to be about 4% and 15.34 W/mm2, respectively. By using this SA, a Q-switched Nd:GdVO4 laser at 1 μm were first realized with the shortest pulse width of 66.8 ns and a maximum repetition rate of 1.13 MHz, respectively. The results indicate that C-QDs may found to be a decent carbon SA material for the high-repetition-rate pulsed laser applications.

In this paper, TiO2 particles (~30 nm) modified with Gd2O3-coating layer (~2 nm) for dye-sensitized solar cells (DSSCs) were fabricated via the hydrothermal method. Among the solar cells based on the Gd3+-doped TiO2 photoanodes, the optimal conversion efficiency was obtained from the 0.025Gd3+-modified TiO2-based cell, with a 17.7% improvement in the efficiency as compared to the unmodified one (7.18%). This enhancement was probably due to the improved UV radiation harvesting via a down-conversion luminescence process by Gd3+ ions, enhancement of visible light absorption and improved dye loading capacity. In addition, after Gd modification, a thin coating could be formed on the TiO2 nanoparticles, which worked as an energy barrier and resulted in a lower charge recombination.

Layered perovskite oxyhalide Bi4NbO8Cl has been reported as a stable photocatalyst for the organic pollutant removal. In this work, Bi4NbO8Cl was synthesized using liquid-combustion approach, and an efficient Ag/Bi4NbO8Cl photocatalyst was prepared via photo-deposition method. Transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) display that metallic Ag nanoparticles (∼10 nm) are uniformly distributed on the surface of Bi4NbO8Cl. Owing to a shift of the valence and conduction band and band-gap narrowing, demonstrated by UV-vis diffuse reflection spectroscopy (UV-vis DRS) and Mott-Schottky results, the Ag/Bi4NbO8Cl show enhanced photocatalytic degradation of RhB with almost 100% within 3 h. Photogenerated holes (h+) are foremost active specie responsible for the degradation of RhB via the capture agent test. The improvement of photocatalytic performance of 3% Ag/Bi4NbO8Cl could be attributed to the synergetic effect of the surface plasmon resonance and electron sinkers by Ag nanoparticles, strengthening the visible-light absorption ability, as well as promoting the separation efficiency of charge carriers, which are beneficial for enhancing photocatalytic performance. The present work provides a promising insight into the design Bi-based photocatalysts to solve environmental pollution.

Heterostructured photocatalysts play a significant role in the removal of contaminants by decreasing the recombination of the photo-induced charges. Herein, we presented novel TiO2/C/BiVO4 ternary hybrids employing a 2D layered Ti3C2 MXene precursor, overcoming the lattice mismatching of TiO2/BiVO4 binary heterostructures simultaneously. Raman and XPS analyses proved the strong coupling effects of TiO2, carbon and BiVO4 components, and the heterostructures were identified from high-resolution transmission electron microscopy results. Moreover, the ternary TiO2/C/BiVO4 composites exhibit excellent photocatalytic performance of Rhodamine B degradation, which is about four times higher than pure BiVO4 and twice that of binary TiO2/BiVO4 heterostructures, reaching a reaction constant of 13.7 × 10-3 min-1 under visible-light irradiation (λ > 420 nm). In addition, for the possible mechanism for dye elimination it was proposed that RhB molecule be directly oxidized by photo-induced holes (h+) on the BiVO4 components and superoxide radical ([Formula: see text]) generated from conduction band electrons of the heterostructures. This work will provide possibilities for developing visible-light responsive nanomaterials for efficient solar utilization.

Monometallic M1(M[Formula: see text] Ni/Cu/Fe/Co) silicates and bimetallic Ni–M2(M[Formula: see text] Cu/Fe/Co) silicates hollow spheres with mesoporous structure and the controllable morphology have been synthesized successfully via one-step sacrificial template method under hydrothermal conditions. The catalysts were obtained by reducing the corresponding silicates in situ under the hydrogen atmosphere at a certain temperature. All the silicates and the catalysts M1/SiO2 and Ni–M2/SiO2 hollow spheres have been characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and temperature-programmed reduction (TPR) thoroughly and systematically. The morphology and reaction conditions of bimetallic Ni–M2 silicates hollow spheres depend on the second metal M2, which has been verified by SEM, TEM and XRD. From the results, it can be concluded that bimetallic silicates possess better physical properties in favor of the catalytic activity. Bimetallic Ni–M2/SiO2 hollow spheres had higher catalytic property than the monometallic M1/SiO2 and the conversion of nitrobenzene could reach 100% within 3[Formula: see text]h using Ni–Cu/SiO2 and Ni–Fe/SiO2 hollow spheres as catalysts.